"We're investigating reports of an issue with Gmail. We will provide more information shortly," it said in a message that was repeated a few times.

For the most part the service was disrupted, but there was a period when services were interrupted and out of order. Google said that under 50 percent of users were affected.

Google posted that everything was back to normal roughly 12 hours later. "The problem with Gmail should be resolved. We apologize for the inconvenience and thank you for your patience and continued support. Please rest assured that system reliability is a top priority at Google, and we are making continuous improvements to make our systems better," it said at 7:00pm PDT.

"As of 1600 Pacific Time, Gmail message delivery and attachment download is functioning normally for all users. We apologize for the duration of today's event; we're aware that prompt email delivery is an important part of the Gmail experience, and today's experience fell far short of our standards."

While the service was struggling Gmail users suffered with delays to emails and attachments. Google says that 29.1 percent of emails were delayed, but added that the median amount of time spent waiting was 2.6 seconds. µ